CA1247710A - Capacitive device and method of packaging that device - Google Patents
Capacitive device and method of packaging that deviceInfo
- Publication number
- CA1247710A CA1247710A CA000463390A CA463390A CA1247710A CA 1247710 A CA1247710 A CA 1247710A CA 000463390 A CA000463390 A CA 000463390A CA 463390 A CA463390 A CA 463390A CA 1247710 A CA1247710 A CA 1247710A
- Authority
- CA
- Canada
- Prior art keywords
- porous metal
- capacitor
- recited
- edge
- capacitive
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000034 method Methods 0.000 title claims abstract description 38
- 238000004806 packaging method and process Methods 0.000 title claims abstract description 37
- 239000003990 capacitor Substances 0.000 claims abstract description 77
- 239000007769 metal material Substances 0.000 claims abstract description 56
- 239000003989 dielectric material Substances 0.000 claims abstract description 10
- 239000000565 sealant Substances 0.000 claims abstract description 10
- 239000002390 adhesive tape Substances 0.000 claims abstract description 4
- 239000002184 metal Substances 0.000 claims description 76
- 229910052751 metal Inorganic materials 0.000 claims description 76
- 239000000356 contaminant Substances 0.000 claims description 36
- 239000010408 film Substances 0.000 claims description 36
- 239000004020 conductor Substances 0.000 claims description 35
- 239000011248 coating agent Substances 0.000 claims description 28
- 238000000576 coating method Methods 0.000 claims description 28
- 238000007789 sealing Methods 0.000 claims description 22
- 239000011104 metalized film Substances 0.000 claims description 20
- 230000001681 protective effect Effects 0.000 claims description 17
- 239000000463 material Substances 0.000 claims description 14
- 230000032798 delamination Effects 0.000 claims description 13
- 239000000835 fiber Substances 0.000 claims description 13
- 239000002654 heat shrinkable material Substances 0.000 claims description 12
- 238000005470 impregnation Methods 0.000 claims description 7
- 239000012799 electrically-conductive coating Substances 0.000 claims description 5
- 238000007499 fusion processing Methods 0.000 claims description 5
- 229910052782 aluminium Inorganic materials 0.000 claims description 4
- XAGFODPZIPBFFR-UHFFFAOYSA-N aluminium Chemical compound [Al] XAGFODPZIPBFFR-UHFFFAOYSA-N 0.000 claims description 4
- 230000004927 fusion Effects 0.000 claims description 4
- 239000007787 solid Substances 0.000 claims description 3
- 238000006073 displacement reaction Methods 0.000 claims description 2
- 239000012530 fluid Substances 0.000 claims 12
- 239000004743 Polypropylene Substances 0.000 claims 2
- 229920000515 polycarbonate Polymers 0.000 claims 2
- 239000004417 polycarbonate Substances 0.000 claims 2
- 229920000728 polyester Polymers 0.000 claims 2
- -1 polypropylene Polymers 0.000 claims 2
- 229920001155 polypropylene Polymers 0.000 claims 2
- 230000002311 subsequent effect Effects 0.000 claims 2
- 230000007613 environmental effect Effects 0.000 claims 1
- 238000004519 manufacturing process Methods 0.000 abstract description 3
- 230000008030 elimination Effects 0.000 abstract description 2
- 238000003379 elimination reaction Methods 0.000 abstract description 2
- 239000004593 Epoxy Substances 0.000 description 6
- 230000007246 mechanism Effects 0.000 description 5
- GZCWPZJOEIAXRU-UHFFFAOYSA-N tin zinc Chemical compound [Zn].[Sn] GZCWPZJOEIAXRU-UHFFFAOYSA-N 0.000 description 5
- 238000005538 encapsulation Methods 0.000 description 4
- 238000005476 soldering Methods 0.000 description 4
- 230000002860 competitive effect Effects 0.000 description 3
- 238000003780 insertion Methods 0.000 description 2
- 230000037431 insertion Effects 0.000 description 2
- 230000008018 melting Effects 0.000 description 2
- 238000002844 melting Methods 0.000 description 2
- 239000007921 spray Substances 0.000 description 2
- 238000006243 chemical reaction Methods 0.000 description 1
- 238000011109 contamination Methods 0.000 description 1
- 230000002708 enhancing effect Effects 0.000 description 1
- 230000003647 oxidation Effects 0.000 description 1
- 238000007254 oxidation reaction Methods 0.000 description 1
- 230000000704 physical effect Effects 0.000 description 1
- 239000012812 sealant material Substances 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000000758 substrate Substances 0.000 description 1
- 238000009834 vaporization Methods 0.000 description 1
- 230000008016 vaporization Effects 0.000 description 1
Classifications
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
- H01G4/002—Details
- H01G4/228—Terminals
- H01G4/232—Terminals electrically connecting two or more layers of a stacked or rolled capacitor
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B23—MACHINE TOOLS; METAL-WORKING NOT OTHERWISE PROVIDED FOR
- B23K—SOLDERING OR UNSOLDERING; WELDING; CLADDING OR PLATING BY SOLDERING OR WELDING; CUTTING BY APPLYING HEAT LOCALLY, e.g. FLAME CUTTING; WORKING BY LASER BEAM
- B23K11/00—Resistance welding; Severing by resistance heating
- B23K11/16—Resistance welding; Severing by resistance heating taking account of the properties of the material to be welded
- B23K11/20—Resistance welding; Severing by resistance heating taking account of the properties of the material to be welded of different metals
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G13/00—Apparatus specially adapted for manufacturing capacitors; Processes specially adapted for manufacturing capacitors not provided for in groups H01G4/00 - H01G11/00
- H01G13/006—Apparatus or processes for applying terminals
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
- H01G4/002—Details
- H01G4/224—Housing; Encapsulation
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01G—CAPACITORS; CAPACITORS, RECTIFIERS, DETECTORS, SWITCHING DEVICES, LIGHT-SENSITIVE OR TEMPERATURE-SENSITIVE DEVICES OF THE ELECTROLYTIC TYPE
- H01G4/00—Fixed capacitors; Processes of their manufacture
- H01G4/002—Details
- H01G4/228—Terminals
Landscapes
- Engineering & Computer Science (AREA)
- Power Engineering (AREA)
- Manufacturing & Machinery (AREA)
- Microelectronics & Electronic Packaging (AREA)
- Mechanical Engineering (AREA)
- Fixed Capacitors And Capacitor Manufacturing Machines (AREA)
Abstract
ABSTRACT OF THE INVENTION
A capacitive device of the parallel plate type capacitor is disclosed with an improved system for packaging such devices.
The devices disclosed have a plurality of strata of capacitive structures formed by alternating layers of dielectric material carrying metallic material thereon with successive layers of metallic material separated by dielectric material. Each layer of metallic material is electrically continuous substantially from the first end to a second end, a first group of the mettalic layers is electrically continuous substantially from a first edge to a first continuity displaced from a second edge and a second group of metallic layers is electrically continuous substantially from a second edge to a second discontinuity displaced from the first edge; the first group alternates with the second group in the capacitive structure. The packaging system includes wrapping means, such as adhesive tape, for protecting the top, the first end, the bottom and the second end of the capacitive device; elec-trical leads connected to the exposed edges of the capacitive device; electrical leads connected to the exposed edges of the capacitive device by a plasma impact connection method; and im-pregnation of the device with a sealant such as wax. The inven-tion provides substantially reduction in cost of manufacture, a significant reduction in volume occupied by the device, superior moisture resistance, improved dissapation factor of the capaci-tive device, and elimination of reflow of the electrical lead connections to the device during mounoting of the device to an assembly such as a printed circuit board.
A capacitive device of the parallel plate type capacitor is disclosed with an improved system for packaging such devices.
The devices disclosed have a plurality of strata of capacitive structures formed by alternating layers of dielectric material carrying metallic material thereon with successive layers of metallic material separated by dielectric material. Each layer of metallic material is electrically continuous substantially from the first end to a second end, a first group of the mettalic layers is electrically continuous substantially from a first edge to a first continuity displaced from a second edge and a second group of metallic layers is electrically continuous substantially from a second edge to a second discontinuity displaced from the first edge; the first group alternates with the second group in the capacitive structure. The packaging system includes wrapping means, such as adhesive tape, for protecting the top, the first end, the bottom and the second end of the capacitive device; elec-trical leads connected to the exposed edges of the capacitive device; electrical leads connected to the exposed edges of the capacitive device by a plasma impact connection method; and im-pregnation of the device with a sealant such as wax. The inven-tion provides substantially reduction in cost of manufacture, a significant reduction in volume occupied by the device, superior moisture resistance, improved dissapation factor of the capaci-tive device, and elimination of reflow of the electrical lead connections to the device during mounoting of the device to an assembly such as a printed circuit board.
Description
47~
IMPROVED C~PACITIVE DEVICE AND METHOD OF PACKAGING THAT
DEVICE
Background of the Invention -The present invention is directed to a capacitive device, specifically a capacitive device which is packaged in a unique manner providing certain advantages in its application such as significant reduction in volume occupied by the device, superior moisture resistance, improved dissipation factor, and elimination of reflow of the electrical connections to the device during mounting of the device to an assembly such as a printed circuit board.
Summary of the Invention The invention in one broad aspect pertains to a capacitive device formed in a solid shape having a length defined by a first end and a second end, a width defined by a first edge and a second edge and a height defined by a top and a bottom, the capacitive device comprising a plurality of strata of capacitive structure, a protective means and electrical connection means. The plurality of strata of capacitive structure comprises a plurality of layers of dielectric film, each of the plurality of layers of dielectric material having affixed thereto a metallic film, the plurality of layers being disposed with the metallic film of each layer being separated by dielectric material from the metallic film of an adjacent layer. Each of the plurality of layers has metal film extending substantially from the first end to the second end and has the metal film electrically discontinuous at a discontinuity between the first edge and the second edge.
The protective means comprises wrapping means covering the top, the first end, the bottom and the second end, and the electrical connection means comprises an electrically conductive coating applied to the first edge and the second edge to electrically connect the metallic films of each of the plurality of layers. The wrapping means is applied 3 ~ sufficiently tightly to the device to mechanically enhance the ~f" device, thereby increasing capability of the device to resist 1;~4~7~3 delamination.
The invention also comprehends a method of attaching leads to a porous metal material comprising the steps of electrically contacting the porous metal material with a first terminal means for applying an electrical potential to the porous metal material, suspending adjacent the porous metal material a second terminal means for applying an electrical potential to the porous metal material, applying an electrical potential across the first terminal means and the second terminal means, and applying a driving force to the second terminal means sufficient to impact and continue to press against the porous metal material sufficiently to complete an electrical circuit between the first terminal means and the second terminal means through the porous metal material.
The invention also comprehends a system for packaging a parallel plate metallized dielectric film capacitive device having a plurality of layers of capacitive strata with alternating layers of metallized dielectric film electrically connected in common respectively at a first edge and at a second edge by an electrically conductive material. The system comprises a wrapping means for protecting the device yet allowing electrical access to the electrically conductive material, electrical lead means for electrically accessing the electrically conductive material, and contaminant displacement means for displacing contaminants from the device and resisting re-entry of contaminants into the device. The wrapping means is configured and applied to provide lateral support to the device sufficient to enhance ability of the device to resist delamination. The electrically conductive material is a porous metal coating applied to the first edge and the second edge, the electrical lead means being attached to the porous metal coating by fusing in a manner providing tenacula of metal fibers embedded within the porous metal coating, thereby providing an extremely strong bond between the lead means and the device.
`` 1;~4~;~71~) A still further aspect of the invention pertains to a method of packaging a metallized film parallel plate capacit-or having alternate plates electrically connected in common at a first edge and remaining alternate plates electrically con-nected in common at a second edge by an electrically conductivematerial, the method comprising the steps of applying protective means for protecting the capacitor from physical and contamina-tive damage in a manner leaving the first edge and the second edge accessible for further processing, attaching electrical lead means for facilitating electrical connection to the capa-citor by percussive fusion of the lead means to the electrically conductive material, and sealing the capacitor to preclude incursion of contaminants.
More particularly, the invention disclosed provides a capacitive device formed in a solid shape generally that of a parallelepiped and having a plurality of strata of capacitive structure made up of a plurality of layers of dielectric film, each of which layers has attached thereto a metallic film.
The layers are disposed in a manner providing separation of metallic film of each layer from metallic film of an adjacent layer by dielectric material. Layers of a first group have metallic film electrically communicative with a first edge of that layer but discontinuous electrically with respect to a second edge of that respective layer. Layers of a second group ~5 have each respective layer carrying a metallic film electrical-ly communicative with the second edge of that respective layer but electrically discontinuous with respect to the first edge of that respective layer. Layers of the first group and the second group are alternated, thereby creating a plurality of strata of capacitive structure. Preferably the device herein is protected by a protective wrapping which is contamination resistant and is applied to the device in a manner conforming to the contour of the device with sufficient strength to provide lateral support to the device and enhance the device's 77 ~
resistance to delamination. In the covering of the device by this protective wrapping the aforementioned edges with which the respective layers of metallic film electrically communicate are left accessible to facilitate electrical connection of leads to the device. The respective edges with which these metal films electrically communicate are coated with a porous metal-lic coating so that the metallic films of the first group of layers are electrically connectèd in common at the first edge of the device and the metallic film layers of the second group of layers are electrically connected in common at the second edge of the device. The electrical leads are attached by a plasma fusion process which provides tenacula of metal fibers within the porous metal coating at each of the edges and there-by provides a strong bond between the electrical leads and the capacitive device. The present invention additionally con-templates impregnation of the device with a sealant, such as wax, to displace air between the wrapping and the capacitive device as well as within the interstices of the capacitive device itself. Thus the dielectric constant of the device is improved since the wax has a higher dielectric constant than the air it has displaced; the wax serves additionally to coat the device thereby further enhancing its resistance to humidity and other contaminants.
The present invention addresses metallized film parallel plate capacitors. Metallized film parallel plate capacitors are presently packaged in a number of ways. For example, insertion within a plastic box and encapsulation within the box by epoxy or a similar material to ensure re-tention of the capacitor within the DOX as well as to enhance the pull away strength of the connection between the electrical leads and the capacitor structure and to environmentally protect the capacitor. Another common means of packaging metallized film parallel plate capacitors is to suspend the capacitors within an epoxy material and thereby to coat the ~g 7'7 ~ ~3 entire capacitor and a small portion of its lead structure with an epoxy material. This packaging method also is designed to environmentally protect the capacitor as well as to enhance pull away strength of the electrical lead-to-capacitor bond. The electrical lead-to-capacitor bond is accomplished in such prior art devices as addressed above by providing a spray metal zinc-tin coating to interconnect alternate layers of metallized film and soldering the electrical leads to that zinc-tin coating. There are certain problems attendant to such a lead connection process, chief among which is the problem of possible reflow of the electrical lead-to-capacitor bond caused by the heat generated on the electrical leads during the process of attaching the leads to an assembly such as a printed circuit board. Such reflow serves to weaken the physical electrical lead-to-capacitor bond and thereby perhaps even alter the electrical quality of the bond as well.
Further, the epoxy and similar materials used to encapsulate capacitors presently are not impervious to moisture or other contaminants and incursion of moisture or other contaminants may occur, thereby altering, perhaps significantly, the electrical characteristics of the encapsulated device.
Further aspects and features of the present invention will be apparent from the following specification and claims when considered in connection with the accompanying drawings illustrating the preferred embodiment of the invention.
Detailed Description of the Drawings Fig. l i5 a perspective drawing of the capacitive device prior to application of sealant material, with tape partially pulled away to illustrate wrapping of tape about the device according to the preferred embodiment of the present in-vention.
Fig. 2 is a schematic drawing representing the capaci-tive device in transverse section and illustrating initial set 6 ~ 5 ~Z~7~7:1~
1 up for attachment of an electrical lead to the capacitive de-vice according to the preferred embodiment of the present invention.
Fig. 3 is a schematic drawing similar to Fig. 2 illus-trating the initial phase of attachment of an electrical leadto the capacitive device according to the preferred embodiment of the present invention.
Fig. 4 is a schematic drawing similar to Figs. 2 and 3 illustrating the final phase of the process of attachment of electrical leads to the capacitive device according to the preferred embodiment of the present invention.
Detailed Description of the Invention A capacitive device 10 is shown in Fig. 1 comprising a plurality of capacitive structures 12 coated at each end with a porous metal conductive material 14 and wrapped with a wrap-ping means such as adhesive tape 16 to provide additionalphysical strength to the capacitive device 10 in order that the capacitive device 10 may better resist delamination of its plurality of capacitive strata 12 and, further, to enhance resistance of the capacitive device 10 to incursions of humid-ity and other contaminants. Of course, other wrapping materi-als, such as heat shrinkable material, could be used in lieu lZ~7 1~
1 of tape. In such an embodiment of the present invention, the heat shrinkable material is applied to the capacitive device 10 and subjected to heat to~form a sleeve about the capacitive device 10 and conforming to the shape thereof. Electrical leads 18 are attached to the capacitive device 10 by fusion with the porous metal conductive material 14 through a process to be described in more detail hereinafter.
An alternative embodiment of the present invention incor-porates thermally insulative tape (or heat shrinkable material which is heat insulative at processing temperatures to which the capacitive device 10 is subjected during mounting to an assembly) is used as wrapping material, thereby allowing the electrical leads 18 to be omitted and enabling mounting of the capacitive device 10 in leadless fashion~
The present invention is designed to provide a capaci-tive device which will be competitive both in terms of price as well as in terms of electrical performance in today's mar-ketplace wherein capacitive devices of the type contemplated by this invention ti.e. metallized film parallel plate capaci-tors) have become essentially commodity items and, as such, extremely price competitive. It is essential that a producer of capacitive devices desiring to remain commercially competi-tive be able to reduce his cost of manufacture as much as pos-sible without reducing the electrical performance of the 1~477 ~3 1 devices. The present invention fulfills both of those essen-tials of the marketplace; in fact, the electrical performance of this device is enhanced while its cost of manufacture is significantly reduced. Prior art devices involve a plurality of capacitive strata with spray metal porous conductive materi-al applied to the ends of the capacitor to electrically con-nect alternate layers of capacitive structure, and attachment of leads to each end through the porous metal conductive mater-ial with a final step of encapsulation of the device in some manner. One common means of encapsulation in today's market-place is insertion of the capacitive device into a plastic box and filling the plastic box with epoxy or a similar material.
Another common means of encapsulation is to dip the capacitive device in epoxy or similar material and thereby coat the capac-itive device and a portion of its lead structure with thematerial. Prior art devices also use a zinc-tin porous metal conductive material on the edges of the device for elec-trical commonality of alternating layers producing the capaci-tive relationship within the device in order to facilitate soldering of electrical leads to the zinc-tin material. Two disadvantages of this soldering means of attachment are that, first, the bond is physically not as strong as i~ desired;
and, second, the electrical lead-to-capacitor bond may be sub-ject to reflow caused by heat conducted by the electrical leads to the joint during attachment of the electrical leads within an electrical assembly, such as a printed circuit board.
~L~47~7~
1 The present invention overcomes both of these problems as will be explained in more detail hereinafter.
Fig. 2 illustrates, schematically, initial set up for plasma fusion of electrical leads to a capacitive device ac-cording to the preferred embodiment of the present invention.
In Fig. 2 a capacitive device lO is shown schematically in transverse section revealing alternating plates of a first group of plates 20 , each of which plates has a layer of dielectric material 21 with metallic film 23 attached thereto and a second group of plates 22 of similarly formed layers of dielectric material 25 and attached metallic film 27 structure.
As is shown in Fig. 2 the first group of plates 20 alternates with the second group of plates 22 with each respective group 20, 22 being aligned within itself yet as a group offset from the other group so that, in Fig. 2, the first group of plates 20 is electrically connected in common by a porous metal con-ductive material 14 and at the left side of Fig. 2 the second group of plates 22 is electrically connected in common by porous metal conductive material 14. (For purposes of clar-ity, similar elements will receive similar reference numerals throughout the various figures.) Continuing to refer to Fig.
IMPROVED C~PACITIVE DEVICE AND METHOD OF PACKAGING THAT
DEVICE
Background of the Invention -The present invention is directed to a capacitive device, specifically a capacitive device which is packaged in a unique manner providing certain advantages in its application such as significant reduction in volume occupied by the device, superior moisture resistance, improved dissipation factor, and elimination of reflow of the electrical connections to the device during mounting of the device to an assembly such as a printed circuit board.
Summary of the Invention The invention in one broad aspect pertains to a capacitive device formed in a solid shape having a length defined by a first end and a second end, a width defined by a first edge and a second edge and a height defined by a top and a bottom, the capacitive device comprising a plurality of strata of capacitive structure, a protective means and electrical connection means. The plurality of strata of capacitive structure comprises a plurality of layers of dielectric film, each of the plurality of layers of dielectric material having affixed thereto a metallic film, the plurality of layers being disposed with the metallic film of each layer being separated by dielectric material from the metallic film of an adjacent layer. Each of the plurality of layers has metal film extending substantially from the first end to the second end and has the metal film electrically discontinuous at a discontinuity between the first edge and the second edge.
The protective means comprises wrapping means covering the top, the first end, the bottom and the second end, and the electrical connection means comprises an electrically conductive coating applied to the first edge and the second edge to electrically connect the metallic films of each of the plurality of layers. The wrapping means is applied 3 ~ sufficiently tightly to the device to mechanically enhance the ~f" device, thereby increasing capability of the device to resist 1;~4~7~3 delamination.
The invention also comprehends a method of attaching leads to a porous metal material comprising the steps of electrically contacting the porous metal material with a first terminal means for applying an electrical potential to the porous metal material, suspending adjacent the porous metal material a second terminal means for applying an electrical potential to the porous metal material, applying an electrical potential across the first terminal means and the second terminal means, and applying a driving force to the second terminal means sufficient to impact and continue to press against the porous metal material sufficiently to complete an electrical circuit between the first terminal means and the second terminal means through the porous metal material.
The invention also comprehends a system for packaging a parallel plate metallized dielectric film capacitive device having a plurality of layers of capacitive strata with alternating layers of metallized dielectric film electrically connected in common respectively at a first edge and at a second edge by an electrically conductive material. The system comprises a wrapping means for protecting the device yet allowing electrical access to the electrically conductive material, electrical lead means for electrically accessing the electrically conductive material, and contaminant displacement means for displacing contaminants from the device and resisting re-entry of contaminants into the device. The wrapping means is configured and applied to provide lateral support to the device sufficient to enhance ability of the device to resist delamination. The electrically conductive material is a porous metal coating applied to the first edge and the second edge, the electrical lead means being attached to the porous metal coating by fusing in a manner providing tenacula of metal fibers embedded within the porous metal coating, thereby providing an extremely strong bond between the lead means and the device.
`` 1;~4~;~71~) A still further aspect of the invention pertains to a method of packaging a metallized film parallel plate capacit-or having alternate plates electrically connected in common at a first edge and remaining alternate plates electrically con-nected in common at a second edge by an electrically conductivematerial, the method comprising the steps of applying protective means for protecting the capacitor from physical and contamina-tive damage in a manner leaving the first edge and the second edge accessible for further processing, attaching electrical lead means for facilitating electrical connection to the capa-citor by percussive fusion of the lead means to the electrically conductive material, and sealing the capacitor to preclude incursion of contaminants.
More particularly, the invention disclosed provides a capacitive device formed in a solid shape generally that of a parallelepiped and having a plurality of strata of capacitive structure made up of a plurality of layers of dielectric film, each of which layers has attached thereto a metallic film.
The layers are disposed in a manner providing separation of metallic film of each layer from metallic film of an adjacent layer by dielectric material. Layers of a first group have metallic film electrically communicative with a first edge of that layer but discontinuous electrically with respect to a second edge of that respective layer. Layers of a second group ~5 have each respective layer carrying a metallic film electrical-ly communicative with the second edge of that respective layer but electrically discontinuous with respect to the first edge of that respective layer. Layers of the first group and the second group are alternated, thereby creating a plurality of strata of capacitive structure. Preferably the device herein is protected by a protective wrapping which is contamination resistant and is applied to the device in a manner conforming to the contour of the device with sufficient strength to provide lateral support to the device and enhance the device's 77 ~
resistance to delamination. In the covering of the device by this protective wrapping the aforementioned edges with which the respective layers of metallic film electrically communicate are left accessible to facilitate electrical connection of leads to the device. The respective edges with which these metal films electrically communicate are coated with a porous metal-lic coating so that the metallic films of the first group of layers are electrically connectèd in common at the first edge of the device and the metallic film layers of the second group of layers are electrically connected in common at the second edge of the device. The electrical leads are attached by a plasma fusion process which provides tenacula of metal fibers within the porous metal coating at each of the edges and there-by provides a strong bond between the electrical leads and the capacitive device. The present invention additionally con-templates impregnation of the device with a sealant, such as wax, to displace air between the wrapping and the capacitive device as well as within the interstices of the capacitive device itself. Thus the dielectric constant of the device is improved since the wax has a higher dielectric constant than the air it has displaced; the wax serves additionally to coat the device thereby further enhancing its resistance to humidity and other contaminants.
The present invention addresses metallized film parallel plate capacitors. Metallized film parallel plate capacitors are presently packaged in a number of ways. For example, insertion within a plastic box and encapsulation within the box by epoxy or a similar material to ensure re-tention of the capacitor within the DOX as well as to enhance the pull away strength of the connection between the electrical leads and the capacitor structure and to environmentally protect the capacitor. Another common means of packaging metallized film parallel plate capacitors is to suspend the capacitors within an epoxy material and thereby to coat the ~g 7'7 ~ ~3 entire capacitor and a small portion of its lead structure with an epoxy material. This packaging method also is designed to environmentally protect the capacitor as well as to enhance pull away strength of the electrical lead-to-capacitor bond. The electrical lead-to-capacitor bond is accomplished in such prior art devices as addressed above by providing a spray metal zinc-tin coating to interconnect alternate layers of metallized film and soldering the electrical leads to that zinc-tin coating. There are certain problems attendant to such a lead connection process, chief among which is the problem of possible reflow of the electrical lead-to-capacitor bond caused by the heat generated on the electrical leads during the process of attaching the leads to an assembly such as a printed circuit board. Such reflow serves to weaken the physical electrical lead-to-capacitor bond and thereby perhaps even alter the electrical quality of the bond as well.
Further, the epoxy and similar materials used to encapsulate capacitors presently are not impervious to moisture or other contaminants and incursion of moisture or other contaminants may occur, thereby altering, perhaps significantly, the electrical characteristics of the encapsulated device.
Further aspects and features of the present invention will be apparent from the following specification and claims when considered in connection with the accompanying drawings illustrating the preferred embodiment of the invention.
Detailed Description of the Drawings Fig. l i5 a perspective drawing of the capacitive device prior to application of sealant material, with tape partially pulled away to illustrate wrapping of tape about the device according to the preferred embodiment of the present in-vention.
Fig. 2 is a schematic drawing representing the capaci-tive device in transverse section and illustrating initial set 6 ~ 5 ~Z~7~7:1~
1 up for attachment of an electrical lead to the capacitive de-vice according to the preferred embodiment of the present invention.
Fig. 3 is a schematic drawing similar to Fig. 2 illus-trating the initial phase of attachment of an electrical leadto the capacitive device according to the preferred embodiment of the present invention.
Fig. 4 is a schematic drawing similar to Figs. 2 and 3 illustrating the final phase of the process of attachment of electrical leads to the capacitive device according to the preferred embodiment of the present invention.
Detailed Description of the Invention A capacitive device 10 is shown in Fig. 1 comprising a plurality of capacitive structures 12 coated at each end with a porous metal conductive material 14 and wrapped with a wrap-ping means such as adhesive tape 16 to provide additionalphysical strength to the capacitive device 10 in order that the capacitive device 10 may better resist delamination of its plurality of capacitive strata 12 and, further, to enhance resistance of the capacitive device 10 to incursions of humid-ity and other contaminants. Of course, other wrapping materi-als, such as heat shrinkable material, could be used in lieu lZ~7 1~
1 of tape. In such an embodiment of the present invention, the heat shrinkable material is applied to the capacitive device 10 and subjected to heat to~form a sleeve about the capacitive device 10 and conforming to the shape thereof. Electrical leads 18 are attached to the capacitive device 10 by fusion with the porous metal conductive material 14 through a process to be described in more detail hereinafter.
An alternative embodiment of the present invention incor-porates thermally insulative tape (or heat shrinkable material which is heat insulative at processing temperatures to which the capacitive device 10 is subjected during mounting to an assembly) is used as wrapping material, thereby allowing the electrical leads 18 to be omitted and enabling mounting of the capacitive device 10 in leadless fashion~
The present invention is designed to provide a capaci-tive device which will be competitive both in terms of price as well as in terms of electrical performance in today's mar-ketplace wherein capacitive devices of the type contemplated by this invention ti.e. metallized film parallel plate capaci-tors) have become essentially commodity items and, as such, extremely price competitive. It is essential that a producer of capacitive devices desiring to remain commercially competi-tive be able to reduce his cost of manufacture as much as pos-sible without reducing the electrical performance of the 1~477 ~3 1 devices. The present invention fulfills both of those essen-tials of the marketplace; in fact, the electrical performance of this device is enhanced while its cost of manufacture is significantly reduced. Prior art devices involve a plurality of capacitive strata with spray metal porous conductive materi-al applied to the ends of the capacitor to electrically con-nect alternate layers of capacitive structure, and attachment of leads to each end through the porous metal conductive mater-ial with a final step of encapsulation of the device in some manner. One common means of encapsulation in today's market-place is insertion of the capacitive device into a plastic box and filling the plastic box with epoxy or a similar material.
Another common means of encapsulation is to dip the capacitive device in epoxy or similar material and thereby coat the capac-itive device and a portion of its lead structure with thematerial. Prior art devices also use a zinc-tin porous metal conductive material on the edges of the device for elec-trical commonality of alternating layers producing the capaci-tive relationship within the device in order to facilitate soldering of electrical leads to the zinc-tin material. Two disadvantages of this soldering means of attachment are that, first, the bond is physically not as strong as i~ desired;
and, second, the electrical lead-to-capacitor bond may be sub-ject to reflow caused by heat conducted by the electrical leads to the joint during attachment of the electrical leads within an electrical assembly, such as a printed circuit board.
~L~47~7~
1 The present invention overcomes both of these problems as will be explained in more detail hereinafter.
Fig. 2 illustrates, schematically, initial set up for plasma fusion of electrical leads to a capacitive device ac-cording to the preferred embodiment of the present invention.
In Fig. 2 a capacitive device lO is shown schematically in transverse section revealing alternating plates of a first group of plates 20 , each of which plates has a layer of dielectric material 21 with metallic film 23 attached thereto and a second group of plates 22 of similarly formed layers of dielectric material 25 and attached metallic film 27 structure.
As is shown in Fig. 2 the first group of plates 20 alternates with the second group of plates 22 with each respective group 20, 22 being aligned within itself yet as a group offset from the other group so that, in Fig. 2, the first group of plates 20 is electrically connected in common by a porous metal con-ductive material 14 and at the left side of Fig. 2 the second group of plates 22 is electrically connected in common by porous metal conductive material 14. (For purposes of clar-ity, similar elements will receive similar reference numerals throughout the various figures.) Continuing to refer to Fig.
2, a first electrical lead 24 is placed in electrical contact with the porous metal conductive material 14 at one end of the capacitor device lO. A second electrical terminal 26, which electrical terminal 26 will ultimately form one of the electri-~4771~3 1 cal leads 18 of Fig. 1, is suspended adjacent the porous metal conductive material 14. Electrical circuitry 28 is used to apply a potential difference between the first electrical lead 24 and the second electrical lead 26 by connections 30 and 32.
Electrical circuit 28 is of the type well known in the art providing for charging of capacitors in order that a large potential may be maintained across its connections 30 and 32 without necessitating power supply requirements beyond those normally found in an industrial environment. Suspended adja-cent the second electrical terminal 26 is a plunger mechanism34 to which a force F will be applied as hereinafter des-cribed.
Referring now to Fig. 3, a subsequent step in attachment of the lead 26 to the porous metal conductive material 14 is shown. At this point the force F has been applied to the plun-ger mechanism 34 to drive the second electrical terminal 26 against the porous metal conductive material 14, thereby com-pleting an electrical circuit between the second electrical terminal 26 and the first electrical terminal 24 through the porous metal conductive material 14. The potential produced by the electrical circuit 28 in the preferred embodiment of the invention is sufficient, in combination with the amount of force F applied to the plunger mechanism 34 and the resultant impact of the second electrical terminal 26 against the porous metal conductive material 14 , to form a plasma 36 within the ~Z47'7 ~3 porous metal conductive material 14 in the vicinity of the second electrical terminal 26. Force F continues to be appli ed to the plunger mechanism 34 to maintain physical and electrical contact between the second electrical terminal 26 and the porous metal conductive material 14 with the result that, with the presence of the plasma 36 in the vicinity of the second electrical terminal 26, the force F, through the plunger mechanism 34, drives the second electrical terminal 26 into the plasma 36 of the porous metal conductive material 14.
As shown in Fig. 4, which figure depicts the final phase of lead attachment according to the preferred embodiment of the present invention, the force F, through the plunger mechan-ism 34, drives the second electrical terminal 2 6 into the porous metal conductive material 14 a distance approximately equal to one-half the diameter of the second electrical termi-nal 26. As the second electrical terminal 26 is driven into the porous metal conductive material 14, the plasma 36 begins to cool and revert to pure metal fibers as at 38 in Fig. 4.
Fig. 4 illustrates the final result of the lead attachment process of the present invention. This final result is parti-cularly advantageous in that the pure metal f ibers 38 are in the f orm of tenacula embedded within the porous metal conduc-tive material 14 and provide an extremely strong physical as well as electrica] bond between the second electrical terminal 26 and the capacitive device 10 through the porous metal con-ductive material 14.
12477~
1 The same procedure as above described for lead attach-ment is applied to the remaining side of the capacitive device 10, and, in subsequent processing, a sealant is introduced by way of vacuum impregnation both within the interstices of the capacitive device 10 as well as between the capacitive device 10 and the tape or other wrapper 16. A common sealant used for such a purpose is wax. Since wax has a higher dielectric constant than the air it is displacing from the interstices of the capacitive device 10 the dielectric constant of the capaci-tive device 10 will be improved by this impregnation process.~oreover, the wax used in the preferred embodiment of the present invention is extremely successful at preventing incur-sions of moisture in humid conditions, a common problem among capacitive devices of the prior art type described above.
The preferred embodiment of the present invention employs a single-metal porous metal conductive material 14 in order that bi-metal reaction enhancement of oxidation will be eliminated; aluminum has been found to be particularly success-ful in this application. Since aluminum has a significantly higher melting point than common zinc-tin materials used as connecting material for prior art capacitors, the problem of reflow during subsequent soldering operations in attaching the capacitor within a subassembly, such as a printed circuit board, is obviated. The inducement of a plasma through the 1~47'~
I application of high potential across the first electrical ter-minal 24 and the second electrical terminal 26 as well as the impact of the plunger means 34 against the second electrical terminal 26 in driving the second terminal 26 against the porous metal conductive rnaterial 14 results in an extremely fast processr sufficiently fast to.insure an excellent physi-cal and electrical bond between the electrical terminal 26 and the capacitive device lO through the porous metal conductive material 14, without any heat damage such as melting or vaporization of the metalllzed films 23, 27 carried upon the dielectric substrates 21, 25 within the capacitive device lO, which met.allized films 23, 27 actually form the capacitor plates of the capacitive device lØ Generally, the fusion process described above for electrical lead attachment occurs in an elapsed time on the order of one millisecond.
It is to be understood that, while the detailed drawings and specific examples given described preferred embodiments of the invention, they are for the purpose of illustration only, that the apparatus of the invention is not limited to the pre-cise details and conditions disclosed and that various changesmay be made therein without departing from the spirit of the invention which is defined by the following claims.
Electrical circuit 28 is of the type well known in the art providing for charging of capacitors in order that a large potential may be maintained across its connections 30 and 32 without necessitating power supply requirements beyond those normally found in an industrial environment. Suspended adja-cent the second electrical terminal 26 is a plunger mechanism34 to which a force F will be applied as hereinafter des-cribed.
Referring now to Fig. 3, a subsequent step in attachment of the lead 26 to the porous metal conductive material 14 is shown. At this point the force F has been applied to the plun-ger mechanism 34 to drive the second electrical terminal 26 against the porous metal conductive material 14, thereby com-pleting an electrical circuit between the second electrical terminal 26 and the first electrical terminal 24 through the porous metal conductive material 14. The potential produced by the electrical circuit 28 in the preferred embodiment of the invention is sufficient, in combination with the amount of force F applied to the plunger mechanism 34 and the resultant impact of the second electrical terminal 26 against the porous metal conductive material 14 , to form a plasma 36 within the ~Z47'7 ~3 porous metal conductive material 14 in the vicinity of the second electrical terminal 26. Force F continues to be appli ed to the plunger mechanism 34 to maintain physical and electrical contact between the second electrical terminal 26 and the porous metal conductive material 14 with the result that, with the presence of the plasma 36 in the vicinity of the second electrical terminal 26, the force F, through the plunger mechanism 34, drives the second electrical terminal 26 into the plasma 36 of the porous metal conductive material 14.
As shown in Fig. 4, which figure depicts the final phase of lead attachment according to the preferred embodiment of the present invention, the force F, through the plunger mechan-ism 34, drives the second electrical terminal 2 6 into the porous metal conductive material 14 a distance approximately equal to one-half the diameter of the second electrical termi-nal 26. As the second electrical terminal 26 is driven into the porous metal conductive material 14, the plasma 36 begins to cool and revert to pure metal fibers as at 38 in Fig. 4.
Fig. 4 illustrates the final result of the lead attachment process of the present invention. This final result is parti-cularly advantageous in that the pure metal f ibers 38 are in the f orm of tenacula embedded within the porous metal conduc-tive material 14 and provide an extremely strong physical as well as electrica] bond between the second electrical terminal 26 and the capacitive device 10 through the porous metal con-ductive material 14.
12477~
1 The same procedure as above described for lead attach-ment is applied to the remaining side of the capacitive device 10, and, in subsequent processing, a sealant is introduced by way of vacuum impregnation both within the interstices of the capacitive device 10 as well as between the capacitive device 10 and the tape or other wrapper 16. A common sealant used for such a purpose is wax. Since wax has a higher dielectric constant than the air it is displacing from the interstices of the capacitive device 10 the dielectric constant of the capaci-tive device 10 will be improved by this impregnation process.~oreover, the wax used in the preferred embodiment of the present invention is extremely successful at preventing incur-sions of moisture in humid conditions, a common problem among capacitive devices of the prior art type described above.
The preferred embodiment of the present invention employs a single-metal porous metal conductive material 14 in order that bi-metal reaction enhancement of oxidation will be eliminated; aluminum has been found to be particularly success-ful in this application. Since aluminum has a significantly higher melting point than common zinc-tin materials used as connecting material for prior art capacitors, the problem of reflow during subsequent soldering operations in attaching the capacitor within a subassembly, such as a printed circuit board, is obviated. The inducement of a plasma through the 1~47'~
I application of high potential across the first electrical ter-minal 24 and the second electrical terminal 26 as well as the impact of the plunger means 34 against the second electrical terminal 26 in driving the second terminal 26 against the porous metal conductive rnaterial 14 results in an extremely fast processr sufficiently fast to.insure an excellent physi-cal and electrical bond between the electrical terminal 26 and the capacitive device lO through the porous metal conductive material 14, without any heat damage such as melting or vaporization of the metalllzed films 23, 27 carried upon the dielectric substrates 21, 25 within the capacitive device lO, which met.allized films 23, 27 actually form the capacitor plates of the capacitive device lØ Generally, the fusion process described above for electrical lead attachment occurs in an elapsed time on the order of one millisecond.
It is to be understood that, while the detailed drawings and specific examples given described preferred embodiments of the invention, they are for the purpose of illustration only, that the apparatus of the invention is not limited to the pre-cise details and conditions disclosed and that various changesmay be made therein without departing from the spirit of the invention which is defined by the following claims.
Claims (47)
1. A capacitive device formed in a solid shape having a length defined by a first end and a second end, a width defined by a first edge and a second edge and a height defined by a top and a bottom, said capacitive device comprising a plurality of strata of capacitive structure, a protective means and electrical connection means; said plurality of strata of capacitive struc-ture comprising a plurality of layers of dielectric film, each of said plurality of layers of dielectric material having affixed thereto a metallic film, said plurality of layers being disposed with said metallic film of each layer being separated by dielec-tric material from said metallic film of an adjacent layer, each of said plurality of layers having metal film extending substan-tially from said first end to said second end and having said metal film electrically discontinuous at a discontinuity between said first edge and said second edge; said protective means com-prising wrapping means covering said top, said first end, said bottom and said second end; and said electrical connection means comprising an electrically conductive coating applied to said first edge and said second edge to electrically connect said metallic films of each of said plurality of layers, and said wrapping means being applied sufficiently tightly to the device to mechanically enhance the device, thereby increasing capability of the device to resist delamination.
2. A capacitive device as recited in claim 1 wherein a first group of said plurality of layers has said discontinuity located at a first distance from said first edge and a second group of said plurality of layers has said discontinuity located at a second distance from said first edge, said first distance and said second distance being unequal; layers of said first group alternating with layers of said second group.
3. A capacitive device as recited in claim 2 wherein said wrapping means comprises tape.
4. A capacitive device as recited in claim 3 wherein said electrically conductive coating comprises a porous metal coating and said electrical connection means further comprises electrical lead means attached to said porous metal coating in a manner providing tenacula of metal fibers embedded within said porous metal coating and fused to said lead means, thereby providing an extremely strong bond between said lead means and the device.
5. A capacitive device as recited in claim 2 wherein said wrapping means comprises a heat shrinkable material applied in encircling relation with respect to the device and subjected to heat to form a sleeve about the device conforming to the shape of the device.
6. A capacitive device as recited in claim 5 wherein said electrically conductive coating comprises a porous metal coating and said electrical connection means further comprises electrical lead means attached to said porous metal coating in a manner pro-viding tenacula of metal fibers embedded within said porous metal coating and fused to said lead means, thereby providing an ex-tremely strong bond between said lead means and the device.
7. A capacitive device as recited in claim 4 wherein said protective means further comprises sealing means, said sealing means being introduced within the device to displace fluid contam-inants from the device, introduced between the device and said tape, and introduced upon exposed surfaces of the device to seal the device against incursions by humidity or other contaminants.
8. A capacitive device as recited in claim 6 wherein said protective means further comprises sealing means, said sealing means being introduced within the device to displace fluid contam-inants from the device, introduced between the device and said heat shrinkable material, and introduced upon exposed surfaces of the device to seal the device against incursions by humidity or other contaminants.
9. An improved system for packaging parallel plate capaci-tive devices having a length defined by a first end and a second end, a height defined by a top and a bottom and a width defined by a first edge and a second edge, said capacitive devices fur-ther having a plurality of strata of capacitive structures formed by alternating layers of dielectreic material carrying metallic material thereon with successive layers of metallic material separated by dielectric material, each layer of metallic material being electrically continuous substantially from said first end to said second end, a first group of said metallic layers being electrically continuous substantially from said first edge to a first discontinuity displaced from said second edge, and a second group of said metallic layers being electrically continuous sub-stantially from said second edge to a second discontinuity dis-placed from said first edge, said first group alternating with said second group; the improvement comprising wrapping means for protecting said top, said first end , said bottom and said second end; electrical connection means for providing electrical connect-ion to said first group of metallic layers at said first edge and separate electrical connection to said second group of metallic layers at said second edge, said wrapping means being applied sufficiently tightly to the device to mechanically enhance the device, thereby increasing capability of the device to resist delamination.
10. An improved system for packaging parallel plate capacitive devices as recited in claim 9 wherein said wrapping means comprises tape.
11. An improved system for packaging parallel plate capaci-tive devices as recited in claim 9 wherein said wrappinng means is heat shrinkable material applied in encircling relation with respect to the device and subjected to heat to form a sleeve about the device conforming to the shape of the device.
12. An improved system for packaging parallel plate capaci-tive devices as recited in claim 10 wherein said tape is ther-mally insulative whereby said capacitive device may be mounted directly to an assembly in leadless fashion.
13. An improved system for packaging parallel plate capaci-tive devices as recited in claim 11 wherein said heat shrinkable material is heat insulative at processing temperatures to which the capacitive device is subjected during mounting of said capaci-tive device to an assembly whereby said capacitive device may be mounted to an assembly in leadless fashion.
14. An improved system for packaging a parallel plate capaci-tive device as recited in claim 10 wherein said electrical con-nection means comprises a porous metal coating applied to said first edge and to said second edge and electrical lead means for facilitating electrical connection to said first and second groups of metallic layers, said lead means being attached to said porous metal coating by a plasma fusion process providing tena-cula of metal fibers embedded within said porous metal coating and fused to said lead means, thereby providing an extremely strong bond between said lead means and said capacitive device.
15. An improved system for packaging a parallel plate capaci-tive device as recited in claim 14 wherein said improved system further comprises sealing means, said sealing means being intro-duced within the capacitive device to displace fluid contaminants from the device, introduced between the device and said wrapping means, and introduced upon exposed surfaces of the capacitive device to seal the device from incursions by humidity and other contaminants.
16. An improved system for packaging a parallel plate capaci-tive device as recited in claim 11 wherein said electrical con-nection means comprises a porous metal coating applied to said first edge and to said second edge and electrical lead means for facilitating electrical connection to said first and second groups of metallic layers, said lead means being attached to said porous metal coating by a plasma fusion process providing tena-cula of metal fibers embedded within said porous metal coating and fused to said lead means, thereby providing an extremely strong bond between said lead means and said capacitive device.
17. An improved system for packaging a parallel plate capaci-tive device as recited in claim 16 wherein said improved system further comprises sealing means, said sealing means being intro-duced within the capacitive device to displace fluid contaminants from the device, introduced between the device and said wrapping means, and introduced upon exposed surfaces of the capacitive device to seal the device from incursions by humidity and other contaminants.
18. A method of attaching leads to a porous metal material comprising the steps of:
(a) electrically contacting the porous metal material with a first terminal means for applying an electri-cal potential to the porous metal material;
(b) suspending adjacent the porous metal material a second terminal means for applying an electrical potential to the porous metal material;
(c) applying an electrical potential across said first terminal means and said second terminal means; and (d) applying a driving force to said second terminal means sufficient to impact and continue to press against the porous metal material sufficiently to complete an electrical circuit between said first terminal means and said second terminal means through the porous metal material.
(a) electrically contacting the porous metal material with a first terminal means for applying an electri-cal potential to the porous metal material;
(b) suspending adjacent the porous metal material a second terminal means for applying an electrical potential to the porous metal material;
(c) applying an electrical potential across said first terminal means and said second terminal means; and (d) applying a driving force to said second terminal means sufficient to impact and continue to press against the porous metal material sufficiently to complete an electrical circuit between said first terminal means and said second terminal means through the porous metal material.
19. A method of attaching leads to a porous metal material as recited in claim 18 wherein said electrical potential and said driving force are sufficient to create a plasma of said porous metal material adjacent said second terminal means and to fuse said second terminal means with the porous metal material upon said impact and during at least a part of said pressing of said second terminal means against said porous metal material.
20. A method of attaching leads to a porous metal material as recited in claim 19 wherein said method further comprises the step of severing said second terminal means at a distance from the porous metal material to form an electrical lead.
21. A system for packaging a parallel plate metallized dielec-tric film capacitive device having a plurality of layers of capac-itive strata with alternating layers of metallized dielectric film electrically connected in common respectively at a first edge and at a second edge by an electrically conductive material, said system comprising a wrapping means for protecting the device yet allowing electrical access to said electrically conductive material, electrical lead means for electrically accessing said electrically conductive material, and contaminant displacement means for displacing contaminants from the device and resisting re-entry of contaminants into the device; said wrapping means being configured and applied to provide lateral support to the device sufficient to enhance ability of the device to resist delamination; said electrically conductive material being a porous metal coating applied to said first edge and said second edge, said electrical lead means being attached to said porous metal coating by fusing in a manner providing tenacula of metal fibers embedded within said porous metal coating, thereby provid-ing an extremely strong bond between said lead means and the device.
22. A method of packaging a metallized film parallel plate capacitor having alternate plates electrically connected in com-mon at a first edge and remaining alternate plates electrically connected in common at a second edge by an electrically conduct-ive material, said method comprising the steps of:
(a) applying protective means for protecting the capaci-tor from physical and contaminative damage in a man-ner leaving said first edge and said second edge accessible for further processing;
(b) attaching electrical lead means for facilitating elec-trical connection to the capacitor by percussive fusion of said lead means to said electrically con-ductive material; and (c) sealing the capacitor to preclude incursion of contam-inants.
(a) applying protective means for protecting the capaci-tor from physical and contaminative damage in a man-ner leaving said first edge and said second edge accessible for further processing;
(b) attaching electrical lead means for facilitating elec-trical connection to the capacitor by percussive fusion of said lead means to said electrically con-ductive material; and (c) sealing the capacitor to preclude incursion of contam-inants.
23. A method of packaging a metallized film parallel plate capacitor as recited in claim 22 wherein said protective means comprises adhesive tape, said tape being sufficiently tightly applied to the capacitor to laterally support the parallel plates and thereby increase the capacitor's resistance to delamination.
24. A method of packaging a metallized film parallel plate capacitor as recited in claim 22 wherein said protective means comprises heat shrinkable material applied in encircling relation with respect to the capacitor and then subjected to heat to form a sleeve about the capacitor, said sleeve conforming to the shape of the capacitor and laterally supporting the parallel plates, thereby increasing the capacitor's resistance to delamination.
25. A method of packaging a metallized film parallel plate capacitor as recited in claim 23 wherein said electrically con-ductive material comprises single-metal porous metal material and said attaching of electrical lead means further comprises, for each of said electrical leads, the steps of:
(a) contacting said porous metal material with a first terminal means for applying an electrical potential to the porous metal material;
(b) suspending adjacent the porous metal material a second terminal means for applying an electrical potential to the porous metal material;
(c) applying an electrical potential across said first terminal means and said second terminal means; and (d) driving said second terminal means toward the capaci-tor with sufficient force to cause said second termi-nal means to impact and continue to press against the porous metal material and to complete an electrical circuit between said first terminal means and said second terminal means through the porous metal materi-al, thereby creating a plasma of the porous metal material in the vicinity of said second terminal means, fusing said second terminal means to said porous metal material, and creating tenacula of metal fibers embedded within said porous metal material.
(a) contacting said porous metal material with a first terminal means for applying an electrical potential to the porous metal material;
(b) suspending adjacent the porous metal material a second terminal means for applying an electrical potential to the porous metal material;
(c) applying an electrical potential across said first terminal means and said second terminal means; and (d) driving said second terminal means toward the capaci-tor with sufficient force to cause said second termi-nal means to impact and continue to press against the porous metal material and to complete an electrical circuit between said first terminal means and said second terminal means through the porous metal materi-al, thereby creating a plasma of the porous metal material in the vicinity of said second terminal means, fusing said second terminal means to said porous metal material, and creating tenacula of metal fibers embedded within said porous metal material.
26. A method of packaging a metallized film parallel plate capacitor as recited in claim 24 wherein said electrically con-ductive material comprises single-metal porous metal material and said attaching of electrical lead means further comprises for each of said electrical leads, the steps of:
(a) contacting said porous metal material with a first terminal means for applying an electrical potential to the porous metal material;
(b) suspending adjacent the porous metal material a second terminal means for applying an electrical potential to the porous metal material;
(c) applying an electrical potential across said first terminal means and said second terminal means; and (d) driving said second terminal means toward the capaci-tor with sufficient force to cause said second termi-nal means to impact and continue to press against the porous metal material and to complete an electrical circuit between said first terminal means and said second terminal means through the porous metal materi-al, thereby creating a plasma of the porous metal material in the vicinity of said second terminal means, fusing said second terminal means to said porous metal material, and creating tenacula of metal fibers embedded within said porous metal material.
(a) contacting said porous metal material with a first terminal means for applying an electrical potential to the porous metal material;
(b) suspending adjacent the porous metal material a second terminal means for applying an electrical potential to the porous metal material;
(c) applying an electrical potential across said first terminal means and said second terminal means; and (d) driving said second terminal means toward the capaci-tor with sufficient force to cause said second termi-nal means to impact and continue to press against the porous metal material and to complete an electrical circuit between said first terminal means and said second terminal means through the porous metal materi-al, thereby creating a plasma of the porous metal material in the vicinity of said second terminal means, fusing said second terminal means to said porous metal material, and creating tenacula of metal fibers embedded within said porous metal material.
27. A method of packaging a metallized film parallel plate capacitor as recited in claim 25 wherein said sealing comprises impregnation of the capacitor with a sealant to displace fluid contaminants from between said wrapping means and the capacitor and from the interstices of the capacitor and to inhibit subse-quent incursion of contaminants into the capacitor.
28. A method of packaging a metallized film parallel plate capacitor as recited in claim 26 wherein said sealing comprises impregnation of the capacitor with a sealant to displace fluid contaminants from between said wrapping means and the capacitor and from the interstices of the capacitor and to inhibit subse-quent incursion of contaminants into the capacitor.
29. A method of packaging a metallized film parallel plate capacitor as recited in claim 25 wherein said single-metal porous metal material is porous aluminum material.
30. A method of packaging a metallized film parallel plate capacitor as recited in claim 26 wherein said single-metal porous metal material is porous aluminum material.
31. A method as recited in claim 27 wherein said film is dielectric film of polyester, polycarbonate or polypropylene, and said sealant is wax.
32. A method as recited in claim 28 wherein said film is dielectric film of polyester, polycarbonate or polypropylene, and said sealant is wax.
33. A capacitive device as recited in Claim 1 wherein a first group of said plurality of layers has said discontinuity located at a first distance from said first edge and a second group of said plurality of layers has said discontinuity located at a second distance from said first edge, said first distance and said second distance being unequal; layers of said first group alternating with layers of said second group; said electrically conductive coating comprises a porous metal coating and said electrical connect-ion means further comprises electrical lead means attached to said porous metal coating in a manner providing tenacula of metal fibers embedded within said porous metal coating and fused to said lead means, thereby providing an extremely strong bond between said lead means and the device.
34. A capacitive device as recited in Claim 33 wherein said wrapping means comprises tape, said tape being applied sufficiently tightly to provide electrical and en-vironmental protection for the device as well as to mechanical-ly enhance the device thereby increasing capability of the device to resist delamination.
35. A capacitive device as recited in Claim 34 wherein said protective means further comprises sealing means, said sealing means being introduced within the device to displace fluid contaminants from the device, introduced between the device and said tape, and introduced upon exposed surfaces of the device to seal the device against incursions by humidity or other contaminants.
36. A capacitive device as recited in Claim 33 wherein said wrapping means comprises a heat shrinkable material applied in encircling relation with respect to the device and subjected to heat to form a sleeve about the device conforming to the shape of the device.
37. A capacitive device as recited in Claim 36 wherein said protective means further comprises sealing means, said sealing means being introduced within the device to displace fluid contaminants from the device, introduced between the device and said heat shrinkable material, and introduced upon exposed surfaces of the device to seal the device against incursions by humidity or other contaminants.
38. An improved system for packaging parallel plate capacitive devices as recited in Claim 9 wherein said electrical connection means comprises a porous metal coating applied to said first edge and to said second edge and electrical lead means for facilitating electrical connection to said first and second groups of metallic layers, said lead means being attached to said porous metal coating by a plasma fusion process providing tenacula of metal fibers embedded within said porous metal coating and fused to said lead means, thereby providing an extremely strong bond between said lead means and said capacitive device.
39. An improved system for packaging parallel plate capacitive devices as recited in Claim 38, wherein said wrapping means comprises tape, said tape being applied sufficiently tightly to provide environmental and elect-rical protection for the device as well as to mechanically enhance the device thereby increasing capability of the device to resist delamination.
40. An improved system for packaging a parallel plate capacitive device as recited in Claim 39 wherein said improved system further comprises sealing means, said sealing means being introduced within the capacitive device to displace fluid contaminants from the device, introduced between the device and said wrapping means, and introduced upon exposed surfaces of the capacitive device to seal the device from incursions by humidity and other contaminants.
41. An improved system for packaging parallel plate capacitive devices as recited in Claim 38 wherein said wrapping means is heat shrinkable material applied in encircling relation with respect to the device and subjected to heat to form a sleeve about the device conforming to the shape of the device.
42. An improved system for packaging a parallel plate capacitive device as recited in Claim 41 wherein said improved system further comprises sealing means, said sealing means being introduced within the capacitive device to displace fluid contaminants from the device, introduced between the device and said wrapping means, and introduced upon exposed surfaces of the capacitive device to seal the device from incursions by humidity and other contaminants.
43. A method of packaging a metallized film parallel plate capacitor having alternate plates electrically connected in common at a first edge and remaining alternate plates electrically connected in common at a second edge by porous metal material, said method comprising the steps of:
(a) applying protective means for protecting the
43. A method of packaging a metallized film parallel plate capacitor having alternate plates electrically connected in common at a first edge and remaining alternate plates electrically connected in common at a second edge by porous metal material, said method comprising the steps of:
(a) applying protective means for protecting the
Claim 43 - cont'd ...
capacitor from physical and contaminative damage in a manner leaving said first edge and said second edge accessible for further processing;
(b) contacting said porous metal material with a first terminal means for applying an electrical potential to the porous metal material;
(c) suspending adjacent the porous metal material a second terminal means for applying an electrical potential to the porous metal material;
(d) applying an electrical potential across said first terminal means and said second terminal means; and (e) driving said second terminal means toward the capacitor with sufficient force to cause said second terminal means to impact and continue to press against the porous metal material and to complete an electrical circuit between said first terminal means and said second terminal means through the porous metal material, thereby creating a plasma of the porous metal material in the vicinity of said second terminal means, fusing said second terminal means to said porous metal material, and creating tenacula of metal fibers embedded within said porous metal material.
capacitor from physical and contaminative damage in a manner leaving said first edge and said second edge accessible for further processing;
(b) contacting said porous metal material with a first terminal means for applying an electrical potential to the porous metal material;
(c) suspending adjacent the porous metal material a second terminal means for applying an electrical potential to the porous metal material;
(d) applying an electrical potential across said first terminal means and said second terminal means; and (e) driving said second terminal means toward the capacitor with sufficient force to cause said second terminal means to impact and continue to press against the porous metal material and to complete an electrical circuit between said first terminal means and said second terminal means through the porous metal material, thereby creating a plasma of the porous metal material in the vicinity of said second terminal means, fusing said second terminal means to said porous metal material, and creating tenacula of metal fibers embedded within said porous metal material.
44. A method of packaging a metallized film parallel plate capacitor as recited in Claim 43 wherein said protect-ive means comprises adhesive tape, said tape being sufficiently tightly applied to the capacitor to laterally support the parallel plates and thereby increase the capacitor's resist-ance to delamination.
45. A method of packaging a metallized film parallel plate capacitor as recited in Claim 44 wherein said method further comprises sealing the capacitor by impregnation of the capacitor with a sealant to displace fluid contamin-ants from between said wrapping means and the capacitor and from the interstices of the capacitor and to inhibit subsequent incursion of contaminants into the capacitor.
46. A method of packaging a metallized film parallel plate capacitor as recited in Claim 43 wherein said protective means comprises heat shrinkable material applied in encircling relation with respect to the capacitor and then subjected to heat to form a sleeve about the capacitor, said sleeve conforming to the shape of the capacitor and laterally supporting the parallel plates, thereby increasing the capacitor's resistance to delamination.
47. A method of packaging a metallized film parallel plate capacitor as recited in Claim 46 wherein said method further comprises sealing the capacitor by impregnation of the capacitor with a sealant to displace fluid contamin-ants from between said wrapping means and the capacitor and from the interstices of the capacitor and to inhibit subsequent incursion of contaminants into the capacitor.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CA000463390A CA1247710A (en) | 1983-11-17 | 1984-09-17 | Capacitive device and method of packaging that device |
Applications Claiming Priority (3)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US06/552,891 US4535381A (en) | 1983-11-17 | 1983-11-17 | Capacitive device and method of packaging that device |
| CA000463390A CA1247710A (en) | 1983-11-17 | 1984-09-17 | Capacitive device and method of packaging that device |
| US552,891 | 1990-07-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1247710A true CA1247710A (en) | 1988-12-28 |
Family
ID=24207241
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000463390A Expired CA1247710A (en) | 1983-11-17 | 1984-09-17 | Capacitive device and method of packaging that device |
Country Status (6)
| Country | Link |
|---|---|
| US (1) | US4535381A (en) |
| EP (2) | EP0355870B1 (en) |
| JP (1) | JPS60113918A (en) |
| CA (1) | CA1247710A (en) |
| DE (2) | DE3485865T2 (en) |
| FI (1) | FI79419C (en) |
Families Citing this family (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| FR2623008B1 (en) * | 1987-11-05 | 1990-03-23 | Dumas Pierre | CYLINDRICAL CAPACITOR FOR ALTERNATING CURRENT WITH AXIAL OUTPUTS |
| US4819115A (en) * | 1988-01-28 | 1989-04-04 | Westinghouse Electric Corp. | End connections for wound capacitors and methods of making the same |
| BR0001310A (en) * | 2000-03-15 | 2001-11-13 | Icotron Ind De Componentes Ele | Capacitor and capacitor manufacturing method |
| US7511497B2 (en) * | 2002-10-24 | 2009-03-31 | The University Of Houston System | Superconducting array of surface MRI probes |
| US8380279B2 (en) * | 2005-05-11 | 2013-02-19 | The University Of Houston System | Intraluminal multifunctional sensor system and method of use |
| US8212554B2 (en) * | 2005-05-11 | 2012-07-03 | The University Of Houston System | Intraluminal magneto sensor system and method of use |
| US20090295385A1 (en) * | 2005-05-11 | 2009-12-03 | Audrius Brazdeikis | Magneto Sensor System and Method of Use |
| CN103454609B (en) * | 2013-09-11 | 2015-10-07 | 国家电网公司 | A kind of capacitive apparatus on-Line Monitor Device debug platform |
Family Cites Families (24)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| GB880169A (en) * | 1900-01-01 | |||
| DE300216C (en) * | ||||
| US2128990A (en) * | 1931-09-26 | 1938-09-06 | Dubilier Condenser Corp | Electrical condenser |
| US2921246A (en) * | 1956-03-29 | 1960-01-12 | Sprague Electric Co | Electrical condensers |
| DE1026454B (en) * | 1956-06-07 | 1958-03-20 | Rueppel & Co Kondensatorenfabr | Method for contacting metallic coatings for capacitors covered with insulating material |
| US3009086A (en) * | 1957-05-06 | 1961-11-14 | Sprague Electric Co | Capacitor terminal connection |
| GB826286A (en) * | 1957-06-27 | 1959-12-31 | Telephone Mfg Co Ltd | Improvements in and relating to welding of capacitors lead-out wires |
| US3067488A (en) * | 1958-02-24 | 1962-12-11 | Gen Electric | Welded structure and welding process for making the same |
| US3134059A (en) * | 1958-08-20 | 1964-05-19 | Illinois Tool Works | Wound capacitor |
| US3150300A (en) * | 1961-04-28 | 1964-09-22 | Sprague Electric Co | Capacitor |
| US3267343A (en) * | 1965-03-01 | 1966-08-16 | Illinois Tool Works | Wound capacitor and lead assembly |
| US3965552A (en) * | 1972-07-24 | 1976-06-29 | N L Industries, Inc. | Process for forming internal conductors and electrodes |
| SE414560B (en) * | 1973-09-07 | 1980-08-04 | Ericsson Telefon Ab L M | PROCEDURE FOR MANUFACTURING CONDENSORS |
| FR2258761A1 (en) * | 1974-01-22 | 1975-08-18 | Materiel Telephonique | Device winding tape around electrical component - perforates tape and cuts tape behind component on table |
| US4071880A (en) * | 1974-06-10 | 1978-01-31 | N L Industries, Inc. | Ceramic bodies with end termination electrodes |
| JPS51111654A (en) * | 1975-03-26 | 1976-10-02 | Marukon Denshi Kk | Method of making organic film capcitors |
| JPS5396465A (en) * | 1977-02-03 | 1978-08-23 | Shinei Kk | Extending method of lead wires of wounddtype capacitor |
| JPS5482066A (en) * | 1977-12-12 | 1979-06-29 | Nissei Electric | Method of producing plastic film capacitor |
| DE2758913C2 (en) * | 1977-12-30 | 1985-01-10 | Siemens AG, 1000 Berlin und 8000 München | Process for the production of stacked electrical capacitors |
| JPS6034810B2 (en) * | 1978-06-09 | 1985-08-10 | 株式会社日立製作所 | Laser trimming method for thick film or thin film capacitors |
| JPS6016090B2 (en) * | 1978-06-12 | 1985-04-23 | 神栄株式会社 | How to pull out lead wires for plastic film capacitors |
| JPS5570016A (en) * | 1979-10-31 | 1980-05-27 | Hitachi Condenser | Method of manufacturing capacitor |
| JPS5943715Y2 (en) * | 1980-09-25 | 1984-12-26 | マルコン電子株式会社 | Multilayer film capacitor |
| JPS58155822U (en) * | 1982-04-09 | 1983-10-18 | 株式会社村田製作所 | ceramic capacitor |
-
1983
- 1983-11-17 US US06/552,891 patent/US4535381A/en not_active Expired - Lifetime
-
1984
- 1984-09-17 CA CA000463390A patent/CA1247710A/en not_active Expired
- 1984-11-02 JP JP59230474A patent/JPS60113918A/en active Granted
- 1984-11-12 DE DE8484307790T patent/DE3485865T2/en not_active Revoked
- 1984-11-12 EP EP89119905A patent/EP0355870B1/en not_active Expired - Lifetime
- 1984-11-12 DE DE3486353T patent/DE3486353T2/en not_active Expired - Fee Related
- 1984-11-12 EP EP84307790A patent/EP0142971B1/en not_active Expired - Lifetime
- 1984-11-16 FI FI844497A patent/FI79419C/en not_active IP Right Cessation
Also Published As
| Publication number | Publication date |
|---|---|
| DE3485865D1 (en) | 1992-09-17 |
| DE3486353T2 (en) | 1995-02-16 |
| FI844497L (en) | 1985-05-18 |
| US4535381A (en) | 1985-08-13 |
| DE3486353D1 (en) | 1994-11-10 |
| FI79419C (en) | 1989-12-11 |
| EP0142971B1 (en) | 1992-08-12 |
| EP0355870A3 (en) | 1990-05-30 |
| EP0142971A3 (en) | 1986-11-20 |
| DE3485865T2 (en) | 1993-02-11 |
| EP0355870A2 (en) | 1990-02-28 |
| EP0142971A2 (en) | 1985-05-29 |
| FI844497A0 (en) | 1984-11-16 |
| JPH0563926B2 (en) | 1993-09-13 |
| JPS60113918A (en) | 1985-06-20 |
| EP0355870B1 (en) | 1994-10-05 |
| FI79419B (en) | 1989-08-31 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |